1 //===------- SemaTemplate.h - C++ Templates ---------------------*- C++ -*-===/
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //===----------------------------------------------------------------------===/
9 // This file provides types used in the semantic analysis of C++ templates.
11 //===----------------------------------------------------------------------===/
12 #ifndef LLVM_CLANG_SEMA_TEMPLATE_H
13 #define LLVM_CLANG_SEMA_TEMPLATE_H
15 #include "clang/AST/DeclTemplate.h"
16 #include "clang/AST/DeclVisitor.h"
17 #include "llvm/ADT/SmallVector.h"
22 /// \brief Data structure that captures multiple levels of template argument
23 /// lists for use in template instantiation.
25 /// Multiple levels of template arguments occur when instantiating the
26 /// definitions of member templates. For example:
29 /// template<typename T>
38 /// When instantiating X<int>::Y<17>::f, the multi-level template argument
39 /// list will contain a template argument list (int) at depth 0 and a
40 /// template argument list (17) at depth 1.
41 class MultiLevelTemplateArgumentList {
43 typedef std::pair<const TemplateArgument *, unsigned> ArgList;
46 /// \brief The template argument lists, stored from the innermost template
47 /// argument list (first) to the outermost template argument list (last).
48 SmallVector<ArgList, 4> TemplateArgumentLists;
51 /// \brief Construct an empty set of template argument lists.
52 MultiLevelTemplateArgumentList() { }
54 /// \brief Construct a single-level template argument list.
56 MultiLevelTemplateArgumentList(const TemplateArgumentList &TemplateArgs) {
57 addOuterTemplateArguments(&TemplateArgs);
60 /// \brief Determine the number of levels in this template argument
62 unsigned getNumLevels() const { return TemplateArgumentLists.size(); }
64 /// \brief Retrieve the template argument at a given depth and index.
65 const TemplateArgument &operator()(unsigned Depth, unsigned Index) const {
66 assert(Depth < TemplateArgumentLists.size());
67 assert(Index < TemplateArgumentLists[getNumLevels() - Depth - 1].second);
68 return TemplateArgumentLists[getNumLevels() - Depth - 1].first[Index];
71 /// \brief Determine whether there is a non-NULL template argument at the
72 /// given depth and index.
74 /// There must exist a template argument list at the given depth.
75 bool hasTemplateArgument(unsigned Depth, unsigned Index) const {
76 assert(Depth < TemplateArgumentLists.size());
78 if (Index >= TemplateArgumentLists[getNumLevels() - Depth - 1].second)
81 return !(*this)(Depth, Index).isNull();
84 /// \brief Clear out a specific template argument.
85 void setArgument(unsigned Depth, unsigned Index,
86 TemplateArgument Arg) {
87 assert(Depth < TemplateArgumentLists.size());
88 assert(Index < TemplateArgumentLists[getNumLevels() - Depth - 1].second);
89 const_cast<TemplateArgument&>(
90 TemplateArgumentLists[getNumLevels() - Depth - 1].first[Index])
94 /// \brief Add a new outermost level to the multi-level template argument
96 void addOuterTemplateArguments(const TemplateArgumentList *TemplateArgs) {
97 TemplateArgumentLists.push_back(ArgList(TemplateArgs->data(),
98 TemplateArgs->size()));
101 /// \brief Add a new outmost level to the multi-level template argument
103 void addOuterTemplateArguments(const TemplateArgument *Args,
105 TemplateArgumentLists.push_back(ArgList(Args, NumArgs));
108 /// \brief Retrieve the innermost template argument list.
109 const ArgList &getInnermost() const {
110 return TemplateArgumentLists.front();
114 /// \brief The context in which partial ordering of function templates occurs.
116 /// \brief Partial ordering of function templates for a function call.
118 /// \brief Partial ordering of function templates for a call to a
119 /// conversion function.
121 /// \brief Partial ordering of function templates in other contexts, e.g.,
122 /// taking the address of a function template or matching a function
123 /// template specialization to a function template.
127 // This is lame but unavoidable in a world without forward
128 // declarations of enums. The alternatives are to either pollute
129 // Sema.h (by including this file) or sacrifice type safety (by
130 // making Sema.h declare things as enums).
131 class TemplatePartialOrderingContext {
134 TemplatePartialOrderingContext(TPOC Value) : Value(Value) {}
135 operator TPOC() const { return Value; }
138 /// \brief Captures a template argument whose value has been deduced
139 /// via c++ template argument deduction.
140 class DeducedTemplateArgument : public TemplateArgument {
141 /// \brief For a non-type template argument, whether the value was
142 /// deduced from an array bound.
143 bool DeducedFromArrayBound;
146 DeducedTemplateArgument()
147 : TemplateArgument(), DeducedFromArrayBound(false) { }
149 DeducedTemplateArgument(const TemplateArgument &Arg,
150 bool DeducedFromArrayBound = false)
151 : TemplateArgument(Arg), DeducedFromArrayBound(DeducedFromArrayBound) { }
153 /// \brief Construct an integral non-type template argument that
154 /// has been deduced, possibly from an array bound.
155 DeducedTemplateArgument(const llvm::APSInt &Value,
157 bool DeducedFromArrayBound)
158 : TemplateArgument(Value, ValueType),
159 DeducedFromArrayBound(DeducedFromArrayBound) { }
161 /// \brief For a non-type template argument, determine whether the
162 /// template argument was deduced from an array bound.
163 bool wasDeducedFromArrayBound() const { return DeducedFromArrayBound; }
165 /// \brief Specify whether the given non-type template argument
166 /// was deduced from an array bound.
167 void setDeducedFromArrayBound(bool Deduced) {
168 DeducedFromArrayBound = Deduced;
172 /// \brief A stack-allocated class that identifies which local
173 /// variable declaration instantiations are present in this scope.
175 /// A new instance of this class type will be created whenever we
176 /// instantiate a new function declaration, which will have its own
177 /// set of parameter declarations.
178 class LocalInstantiationScope {
180 /// \brief A set of declarations.
181 typedef SmallVector<Decl *, 4> DeclArgumentPack;
184 /// \brief Reference to the semantic analysis that is performing
185 /// this template instantiation.
188 typedef llvm::DenseMap<const Decl *,
189 llvm::PointerUnion<Decl *, DeclArgumentPack *> >
192 /// \brief A mapping from local declarations that occur
193 /// within a template to their instantiations.
195 /// This mapping is used during instantiation to keep track of,
196 /// e.g., function parameter and variable declarations. For example,
200 /// template<typename T> T add(T x, T y) { return x + y; }
203 /// when we instantiate add<int>, we will introduce a mapping from
204 /// the ParmVarDecl for 'x' that occurs in the template to the
205 /// instantiated ParmVarDecl for 'x'.
207 /// For a parameter pack, the local instantiation scope may contain a
208 /// set of instantiated parameters. This is stored as a DeclArgumentPack
210 LocalDeclsMap LocalDecls;
212 /// \brief The set of argument packs we've allocated.
213 SmallVector<DeclArgumentPack *, 1> ArgumentPacks;
215 /// \brief The outer scope, which contains local variable
216 /// definitions from some other instantiation (that may not be
217 /// relevant to this particular scope).
218 LocalInstantiationScope *Outer;
220 /// \brief Whether we have already exited this scope.
223 /// \brief Whether to combine this scope with the outer scope, such that
224 /// lookup will search our outer scope.
225 bool CombineWithOuterScope;
227 /// \brief If non-NULL, the template parameter pack that has been
228 /// partially substituted per C++0x [temp.arg.explicit]p9.
229 NamedDecl *PartiallySubstitutedPack;
231 /// \brief If \c PartiallySubstitutedPack is non-null, the set of
232 /// explicitly-specified template arguments in that pack.
233 const TemplateArgument *ArgsInPartiallySubstitutedPack;
235 /// \brief If \c PartiallySubstitutedPack, the number of
236 /// explicitly-specified template arguments in
237 /// ArgsInPartiallySubstitutedPack.
238 unsigned NumArgsInPartiallySubstitutedPack;
240 // This class is non-copyable
241 LocalInstantiationScope(const LocalInstantiationScope &);
242 LocalInstantiationScope &operator=(const LocalInstantiationScope &);
245 LocalInstantiationScope(Sema &SemaRef, bool CombineWithOuterScope = false)
246 : SemaRef(SemaRef), Outer(SemaRef.CurrentInstantiationScope),
247 Exited(false), CombineWithOuterScope(CombineWithOuterScope),
248 PartiallySubstitutedPack(0)
250 SemaRef.CurrentInstantiationScope = this;
253 ~LocalInstantiationScope() {
257 const Sema &getSema() const { return SemaRef; }
259 /// \brief Exit this local instantiation scope early.
264 for (unsigned I = 0, N = ArgumentPacks.size(); I != N; ++I)
265 delete ArgumentPacks[I];
267 SemaRef.CurrentInstantiationScope = Outer;
271 /// \brief Find the instantiation of the declaration D within the current
272 /// instantiation scope.
274 /// \param D The declaration whose instantiation we are searching for.
276 /// \returns A pointer to the declaration or argument pack of declarations
277 /// to which the declaration \c D is instantiataed, if found. Otherwise,
279 llvm::PointerUnion<Decl *, DeclArgumentPack *> *
280 findInstantiationOf(const Decl *D);
282 void InstantiatedLocal(const Decl *D, Decl *Inst);
283 void InstantiatedLocalPackArg(const Decl *D, Decl *Inst);
284 void MakeInstantiatedLocalArgPack(const Decl *D);
286 /// \brief Note that the given parameter pack has been partially substituted
287 /// via explicit specification of template arguments
288 /// (C++0x [temp.arg.explicit]p9).
290 /// \param Pack The parameter pack, which will always be a template
293 /// \param ExplicitArgs The explicitly-specified template arguments provided
294 /// for this parameter pack.
296 /// \param NumExplicitArgs The number of explicitly-specified template
297 /// arguments provided for this parameter pack.
298 void SetPartiallySubstitutedPack(NamedDecl *Pack,
299 const TemplateArgument *ExplicitArgs,
300 unsigned NumExplicitArgs);
302 /// \brief Retrieve the partially-substitued template parameter pack.
304 /// If there is no partially-substituted parameter pack, returns NULL.
305 NamedDecl *getPartiallySubstitutedPack(
306 const TemplateArgument **ExplicitArgs = 0,
307 unsigned *NumExplicitArgs = 0) const;
310 class TemplateDeclInstantiator
311 : public DeclVisitor<TemplateDeclInstantiator, Decl *>
314 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex;
316 const MultiLevelTemplateArgumentList &TemplateArgs;
318 /// \brief A list of out-of-line class template partial
319 /// specializations that will need to be instantiated after the
320 /// enclosing class's instantiation is complete.
321 SmallVector<std::pair<ClassTemplateDecl *,
322 ClassTemplatePartialSpecializationDecl *>, 4>
323 OutOfLinePartialSpecs;
326 TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
327 const MultiLevelTemplateArgumentList &TemplateArgs)
328 : SemaRef(SemaRef), SubstIndex(SemaRef, -1), Owner(Owner),
329 TemplateArgs(TemplateArgs) { }
331 // FIXME: Once we get closer to completion, replace these manually-written
332 // declarations with automatically-generated ones from
333 // clang/AST/DeclNodes.inc.
334 Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
335 Decl *VisitLabelDecl(LabelDecl *D);
336 Decl *VisitNamespaceDecl(NamespaceDecl *D);
337 Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
338 Decl *VisitTypedefDecl(TypedefDecl *D);
339 Decl *VisitTypeAliasDecl(TypeAliasDecl *D);
340 Decl *VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
341 Decl *VisitVarDecl(VarDecl *D);
342 Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
343 Decl *VisitFieldDecl(FieldDecl *D);
344 Decl *VisitIndirectFieldDecl(IndirectFieldDecl *D);
345 Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
346 Decl *VisitEnumDecl(EnumDecl *D);
347 Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
348 Decl *VisitFriendDecl(FriendDecl *D);
349 Decl *VisitFunctionDecl(FunctionDecl *D,
350 TemplateParameterList *TemplateParams = 0);
351 Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
352 Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
353 TemplateParameterList *TemplateParams = 0,
354 bool IsClassScopeSpecialization = false);
355 Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
356 Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
357 Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
358 ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
359 Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
360 Decl *VisitClassTemplatePartialSpecializationDecl(
361 ClassTemplatePartialSpecializationDecl *D);
362 Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
363 Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
364 Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
365 Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
366 Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
367 Decl *VisitUsingDecl(UsingDecl *D);
368 Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
369 Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
370 Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
371 Decl *VisitClassScopeFunctionSpecializationDecl(
372 ClassScopeFunctionSpecializationDecl *D);
374 // Base case. FIXME: Remove once we can instantiate everything.
375 Decl *VisitDecl(Decl *D) {
376 unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
377 DiagnosticsEngine::Error,
378 "cannot instantiate %0 yet");
379 SemaRef.Diag(D->getLocation(), DiagID)
380 << D->getDeclKindName();
386 SmallVectorImpl<std::pair<ClassTemplateDecl *,
387 ClassTemplatePartialSpecializationDecl *> >
389 delayed_partial_spec_iterator;
391 /// \brief Return an iterator to the beginning of the set of
392 /// "delayed" partial specializations, which must be passed to
393 /// InstantiateClassTemplatePartialSpecialization once the class
394 /// definition has been completed.
395 delayed_partial_spec_iterator delayed_partial_spec_begin() {
396 return OutOfLinePartialSpecs.begin();
399 /// \brief Return an iterator to the end of the set of
400 /// "delayed" partial specializations, which must be passed to
401 /// InstantiateClassTemplatePartialSpecialization once the class
402 /// definition has been completed.
403 delayed_partial_spec_iterator delayed_partial_spec_end() {
404 return OutOfLinePartialSpecs.end();
407 // Helper functions for instantiating methods.
408 TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
409 SmallVectorImpl<ParmVarDecl *> &Params);
410 bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
411 bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
413 TemplateParameterList *
414 SubstTemplateParams(TemplateParameterList *List);
416 bool SubstQualifier(const DeclaratorDecl *OldDecl,
417 DeclaratorDecl *NewDecl);
418 bool SubstQualifier(const TagDecl *OldDecl,
421 Decl *InstantiateTypedefNameDecl(TypedefNameDecl *D, bool IsTypeAlias);
422 ClassTemplatePartialSpecializationDecl *
423 InstantiateClassTemplatePartialSpecialization(
424 ClassTemplateDecl *ClassTemplate,
425 ClassTemplatePartialSpecializationDecl *PartialSpec);
429 #endif // LLVM_CLANG_SEMA_TEMPLATE_H